The Hempstead Plains is a region of central Long Island, in what is now Nassau County, in New York State. It was once an open expanse of native grassland estimated to once extend to about . It was separated from the North Shore of Long Island by the Harbor Hill Moraine, later approximately Route 25. The modern Hempstead Turnpike approximately traces the separation of the plain from the South Shore of Long Island. The east–west extent was from somewhat west of the modern Queens, New York City border to slightly beyond the Suffolk County border. The Town of Hempstead, now America's most populous civil township, was first settled by Europeans around 1644. Although the settlers were from the English colony of Connecticut, a patent was issued by Dutch New Netherland after the settlers had purchased land from the local Native Americans. The town may have been named for either Hemel Hempstead in England, or the city of Heemstede in North Holland. In early US history, the Hempstead Plains region was cited as one of the few natural prairies east of the Allegheny Mountains. Long Island historians George Dade and Frank Strand wrote that it was created by an outwash of glacial sediment more than ten thousand years ago. The result was vast, flat open land. The site is considered highly ecologically and historically significant. The Hempstead Plains supports populations of federally endangered and globally rare plants among its 250 different kinds of vegetation as well as several plant species that are now considered rare in New York State. It represents one of the most rapidly vanishing habitats in the world, along with scores of birds, butterflies, and other animals that are vanishing with it. Horse racing Horse racing in the United States and on the North American continent dates back to the establishment of the Newmarket course on the Salisbury Plains section of the Hempstead Plains of Long Island in 1665. This first racing meet in North America was supervised by New York's colonial governor, Richard Nicolls. The area is now occupied by the present Nassau County region of Greater Westbury and Garden City. The year 1905 saw the opening of Belmont Park on part of the western edge of the Hempstead Plains. Its mile and a half main track is the largest dirt Thoroughbred race course in the world, and it has the sport's largest grandstand. The South Westbury